Grate control mechanism



Feb. 14, 1933. 5. A. KOHOUT GRATE CONTROL MECHANISM Filed Aug. 27, 1928 4 Sheets-Sheet l I Q] fz erzr Geoff/i W 7 2 Feb. 14, 1933. G. A. KOHOUT GRATE CONTROL MECHANISM Filed. Aug. 27, 1928 4 Sheets-Sheet 2 frzaezzz ar Gea/ye/ZI QOuZ f)? Mr Feb. 14,- 1933. G, A, KQHOUT 1,897,579

GRATE CONTROL MECHANISM Filed Aug. 27, 1928 4 Sheets-Sheet 3 Feb. 14, 1933. G. A. KOHOUT 1,897,579

GRATE common MECHANISM Filed Aug. 27, 1928 4 Sheets-Sheet 4 Patented Feb. 14, 1933 UNITED STATES GEORGE A. KOHOUT, OF CHICAGO, ILLINOIS GRATE oon'rnor. MECHANISM Application filed August 27, 1928.

My invention relates to grate control mechanism for furnaces, and more particularly to means for automatically operating stoker grates at intervals during the burnin of fuel thereon so as to avoid the necessity having this work done manually by the attendant, and probably not done at the proper time.

It is also a purpose of this invention to provide means for automatically rocking the stoker grates at certain definite time intervals during the operation of the furnace.

It is also a purpose of this invention to provide novel means for regulating the stroke or amount of rocking movement imparted to the grate bars.

Another object of the invention is to provide a novel means for varying at will the period between successive rockin operations of the grates so as to provide for rapid or slow operation of the furnace, as may be necessary.

It is also an object of this invention to provide a novel means to insure the return of the grate bars to closed position after each rocking operation thereof.

A further and more particular object of the invention is to provide, in connection with the driving mechanism for rocking the grates, automatic control means to insure the return of the grates to the proper closed position after each rocking operation before the driving mechanism for rocking the grates has the power released therefrom.

Other objects and advantages of the invention will appear as the description proceeds, in connection with the accompanying drawings, wherein the preferred form of the invention is shown. However, I wish it to be understood that I do not intend to limit myself to the exact details shown and described, but that I intend to avail myself of all such modifications as will occur to one skilled in this art and as fall within the scope of the claims.

In the drawings, 7

Fig. 1 is a section taken longitudinally through the furnace, showing the grate mechanism and illustrating the connection of my operating mechanism thereto;

Fig. 2 is an enlarged detail view of the Serial N0. 302,395.

driving shaft and the mechanism employed to impart a rocking movement to the grates;

Fig. 3 is a front view taken at right angles to Fig. 2, illustrating the same mechanism;

Fig. 4 is a section on the line 4.4 of Fig. 3;

Fig. 5 is a section on the line 55 of F i 3;

Fig. 6 is a diagrammatic front view of the furnace with parts omitted, illustrating the application of the grate control mechanism thereto and the power unit for driving the 50 same;

Fig. 7 is a wiring diagram, illustrating the wiring circuit for the motor employed in driving the mechanism.

.Fig. 8 is a detailed side viewv taken at the 55 left of Fig. 6 between the motor and the drive shaft.

Referring now in detail to the drawings, the numeral 10 indicates a driving motor which is connected through reduction gearing to a rotating crank 11 that is in turn connected by means of a link 12 to a crank arm 13 on the shaft 14, so that upon rotation of the crank 11 a rocking movement will be imparted to the shaft 14. This rocking movement preferably is of such an extent as to give an angular movement to the shaft of about fiftyone degrees. Mounted on the shaft adjacent the opposite ends thereof are a pair of units 15 and 16 which serve to transmit at certain intervals the rocking movement of the shaft, or a portion thereof, to the bars 17, which are connected, as shown in Fig. 1, to the grate bar mechanism at 18, so that upon movement of the bars 17'the grate bars 19 will be rocked about their pivots 20 to move the fuel thereon downwardly toward the ash-dumping plate 21. The ash dump, however, is not automatically operated, but is operated by means of a hand bar 22 whenever desired.

Referringnow more particularly to the detailed Figures 2 to 5 of the mechanism for transmitting the rocking movement of the shaft to the member 17, this mechanism consists of a member 23 secured by means of the key 24 upon the drive shaft 14: so as to rock therewith continuously. This member 23 has the laterally projecting arm 25, which in turn carries the stub shaft 26 upon which the dogs 27 and 28 are mounted. Opposite cam member is normally held stationary by means of the lug 32 thereon and the set screw 33 extending through the lug into engagement with teeth 34 upon the flange 35 forming a. part of the bearing 36 for the shaft 14. This cam member, as will be clear from an inspection of Fig. 2, has a portion extending above the ratchet teeth on the wheel 30 to the point 37 when the cam extends inwardly and encircles the shaft 14. The distance of the point 37 angularly about the shaft 14 from the position shown in Fig. 2 may, of course, be varied by changing the setting of the set screw 33 on the teeth 34 of the member 35. This cam member 31, as shown in Fig. 3, engages with the dog 28 throughout a portion of its travel when the arm 25 is rocked with the shaft 14. However, as the point of the dog 28 passes over the end of the cam at 37, the dog drops into engagement with the teeth of the ratchet wheel 30 to impart a certain amount of rotation thereto, depending upon the setting of the cam 31.

The ratchet wheel 30 has on one side thereof a cam member 38, which member, as shown in Fig. 2, is substantially circular in outline with the exception of the cut-away portion between the shoulders 39 and 40, which provide a recess to receive the end of the dogi27 at certain intervals. Normally, the cam 38 holds the dog 27 upon the outer, circular face thereof while the dog 28 is moving the ratchet wheel 30 step by step under the successive rocking motions of the shaft 14. Upon a complete revolution of the ratchet wheel 30, however, the shoulder 39 will be reached by the dog 27 in its travel over the cam, at which time it will drop down into the recess formed in the cam between the shoulders 39 and 40. Thereupon, upon the next rocking movement of the shaft 14 in a direction to move the ratchet wheel, the dog 27 will, in moving forward, engage the shoulder 41 formed upon the member 42 that is pivotally mounted upon the shaft 14. This member 42, as shown clearly in Fig. 2, depends from the shaft 14 and has the arm 43 secured to the bar 17, so that if the member 42 is rocked about the shaft 14, motion will be imparted to the bar 17 to rock the grates, as hereinbefore described.- The dog 27 in this manner is caused to rock the member 42 once upon each revolution of the ratchet wheel30 to rock the grates, and, of course, the number of times the shaft 14 rocks to produce one revolution of the ratchet wheel 30 depends upon the set ting of the cam member 31 to adjust the length of throw caused by the dog 28 engaging the ratchet wheel 30.

After the dog 27 has, by engagement with the shoulder 41, moved the member 42 to rock the grates out of normal closed position, the grates will again be moved to closed position as the shaft 14 rocks in the opposite direction by means of the engagement of the abutment 29 with a similar abutment 44 provided on the member 42 in position to be engaged by the abutment 29 as the member 23 rocks with the shaft 14. V

The member 42 is provided also with an opening at 45 so that the same may be'handoperated to-rock the grates if forany reason the automatic operating mechanism is out of order. The bearing 36 for the shaft 14 carries a short stub shaft 46, upon which shaft there is pivoted a dog 47 adapted to engage with the teeth of the ratchet wheel 30 to prevent its being rotated in the wrong direction by its frictional engagement with the shaft 14 when the shaft is being rocked in a counter-clockwise direction, as shown in Fig. 2. The pressure of this dog is-adjustable by means of the bolt 48 and the spring 49 so that it can by sufficient force from the spring 49 hold it in place and at the same timeperunit the dog 28 to rotate the ratchet wheel 30. I A pin 50 is provided on the arm 25 to engage the dog 27 in case it is thrown back for any purpose to prevent its engagement with the cam 38 and the shoulder 39 on the member 42. Thus the dog 28 may be thrown back against the pin 50 so as to cut out the operation of the member '42 by means of this dog and still permit the shaft 14, which may operate other mechanism throughout the furnace, to continue its rocking motion without rocking the grates.

In operating this device, if the shaft 14 continues to rock, the member 23 will, of course, through the medium of the abutment 29 and the abutment 44, insure the return after each rocking of the grates of the member 42 into proper position to leave the grates level, as shown in Fig. 1. If, however, the

motor circuit should be opened by means of the main switch indicated at 51, it might stop the rocking of the shaft 14 in such a position as to leave the grates rocked upwardly so as to let the fire down in between them, and thus burn out the grates. To avoid this difficulty, I have provided in the motor circuit an auxiliary switch 52 in parallel with the main, manually-operated switch 51, which switch normally is closed when the motor is in operation, and is adapted to be'opened by .pressure'upon a button, as illustrated at 53 in Fig. 6. The shaft 14 has thereon an arm 54 which is adapted to engage the button 53 on the switch and open the switch when the shaft is rocked to the extreme position illustrated in Fig. 2and in Fig. 1, to hold the grates in proper level position. At other times the arm 54, rocking with the shaft 14, alternately opens and closes the switch 52. This, however,

has no effect upon the operation of the motor so long as switch 51 is closed. But since the switch 52 is normally closed except when the shaft is in the position hereinbefore referred to, in case the switch 51 is open at such time as to stop the shaft in any other position, the switch 52 will remain closed until the shaft moves to the proper position to level the grates, at which time it opens the switch 52 by pressing upon the button 53. This insures the proper leveling of the grates at all times regardless of whether the motor is running or is manually stopped for some reason.

With the above description, it is thought that the construction and advantages of this invention will be clear to those skilled in this art, and having thus described my invention, what I claim as new and desire to secure by Letters Patent is 1. Grate control mechanism for stokers of the rocking grate type comprising a rocking grate a member operatively connected to the grate for rocking the same, a rocking drive shaft, power means for continuously rocking said shaft, connecting means between said shaft and member for periodically causing said shaft to move said member and thereby rock said grate and return the same to normal position, and means associated with said power means and shaft insuring return of the grate to normal position when said power means is stopped.

2. In a device of the character described, a driving motor, a current supply circuit therefor, a shaft, means connecting said shaft and motor for imparting a rocking motion to said shaft, a stoker grate, means connecting said grate and shaft for rocking said grate from normal position into fuel advancing position and back, the current supply circuit for said motor having two circuit opening devices in parallel with each other, one of said devices being operable independently of the shaft, and means actuated by the shaft controlling the other of said devices to open it only when the grates are in normal position.

In witness whereof, I hereunto subscribe my name this 17th day of July, A. D. 1928.

GEORGE A. KOHOUT. 

